// 组合函数
function compose(f, g) {
  return function (value) {
    return f(g(value));
  };
}

function reverse(array) {
  return array.reverse();
}

function first(array) {
  return array[0];
}

const last = compose(first, reverse);
console.log(last([1, 2, 3, 4]));
